> We said knowledge was being lost, now I am sure of it.
Tsk. Poor reasoning there :-) The worst case scenario
here is that *someone* has lost some knowledge; but to
get that far you would have to show that hw knew it in
the first place :-)
Actually, I only have a tenuous grasp (for some suitable
value of "tenuous") of how the thing works anyway. I've
only ever possessed one, it currently still seems to
cook as well (or badly) as it ever did so I've had no
cause to examine it in any detail. If it breaks, it will
get looked at (although I suspect, without ever having
checked, that a new megnetron will cost a significant
fraction of the price of a microwave oven). Still,
there's always the chance that the controller or its
keypad will give up the ghost.
> I am almost sure the trnasmitter output stages are still
> valve-based, at
> least on larger transmitters.
AFAIK they are. I remember reading an article in (I think)
one of the IEE rags some time ago that described some new
generation of semiconductors that could handle the combination
of power and frequency, but they were only being used in
specialised applications because of the cost. I assume that
your average TV transmitter mast will stay with valves for
a while yet.
> I wouldn't want to bet on that. I certainly wouldn't want to try to
> design a microwave oscillator using semiconductors of
> sufficient power
> for a large radar system.
If "large" == "big enough to fry the occasional bird",
I think I'd tend to agree!
Antonio
--
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Antonio Carlini arcarlini_at_iee.org
Received on Tue Jun 22 2004 - 13:12:58 BST